HORN, Horn of Africa, one health, Eritrea, Ethiopia, Djibouti, Kenya, Somalia, South Sudan, Sudan, Uganda, Somaliland, leptospirosis, cysticercosis, bovine tuberculosis, rabies, leishmaniasis, brucellosis, echinococcosis, toxoplasmosis, Q fever, trypanosomiasis, anthrax, hepatitis E, Rift Valley fever, scoping review,